@Taiwan85 I was in a similar position a few months ago. I owned a 2002 wrx between 2006 and 2010 and spent a small fortune on modifying it. Basically what I ended up with after spending thousands of pounds was what I would have had if I'd of just bought an sti.
So this time it had to be an sti. The difference between wrx and sti in standard form is huge. Stronger engine, bigger brakes, stronger 6 speed gearbox, stronger clutch, better suspension, nicer interior, more power, dccd, better wheels, all the exterior modifications like big spoiler etc....
i had a slightly bigger budget than you so a few more options and decided I wanted a blob or hawk sti. Test drove a couple of blobs and liked them, then test drove a hawk and fell in love there and then. Much better in my opinion.
I think what puts people off the hawk is the 2.5 engine is fairly well known for ringlands and head gasket failure. But any scooby can throw up a big bill so I wouldn't buy based soley on that.
Also most tuners will tell you that the best engine for an impreza is a forged 2.5. So if it does go just forge it and bang it back in. (I've set a couple of k's aside specifically for this purpose.)
If you do go blob, which I'd reccomend with an £8k budget, deffo get the sti and I guarantee you'll love it 😁